JPS62267559A - Suction device for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve combustion efficiency through increase of an absolute amount of oxygen, fed to an engine, without increasing the heat capacity of a production system, by a method wherein an oxygen enriching system is located in a suction system. CONSTITUTION:The suction system of an internal combustion engine 1 comprises a main intake air passage 2a and an auxiliary intake air passage 2b, both being formed as in a conventional type. An oxygen enriching means 3 is located in the auxiliary intake air passage 2b. The oxygen enriching means 3 is formed by a tough film, serving as a filter material 3a, which is made of a high molecular material having an oxygen transmission factor of 2-3X10<-8>(cm<3>.cm/cm<3> sec.CmHg) or more, a ratio alpha between oxygen and nitrogen transmission factors of at least 2 or more, and a thickness of 1-0.1mum.

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to an intake system for an internal combustion engine, and more specifically, an intake system that allows a large amount of oxygen necessary for combustion to be taken into a combustion chamber. It is related to.

<Prior Art> In order to increase the combustion efficiency of an internal combustion engine and improve fuel efficiency, in recent years, various types of A supply means are often installed in the engine.

<Problems to be Solved by the Invention> By the way, when a large amount of air is supplied into the combustion chamber using the supercharging means as described above, although the absolute amount of oxygen in the combustion chamber increases, the absolute amount of nitrogen increases. Therefore, there was a problem in that even if the supercharging rate was increased, the combustion efficiency could not necessarily be increased.

That is, combustion is an oxidation reaction of fuel, and when a fuel containing no impurities (a compound of carbon and hydrogen) is burned with only oxygen, carbon dioxide gas and water are produced. In addition, the temperature of the flame is determined by the heat capacity of the production system and the heat generated, but in reality, since combustion is performed with air, nitrogen is added to the production system, and the heat capacity of the production system increases by this amount of nitrogen, causing the flame to increase. The temperature will drop.

Therefore, if only a large amount of air is supplied into the combustion chamber using conventional supercharging means, the increase ratio of oxygen and nitrogen will be the same, so even if the supercharging rate is increased, the flame will not increase. The problem is that the temperature does not rise that much, and in fact, as the supercharging rate increases, the pumping loss increases and the exhaust flow rate also increases, so overall fuel efficiency cannot necessarily be made sufficiently high. there were.

The present invention was made in view of these circumstances, and provides a novel intake device that can increase the absolute amount of oxygen used for fuel combustion without significantly increasing the heat capacity of the generation system. The purpose of this is to improve the fuel efficiency of an internal combustion engine without causing secondary problems such as an increase in exhaust flow rate.

Means for Solving the Problems> In order to achieve the above object, the present invention provides a gas component Il! using a polymeric material. The engine is characterized by having an oxygen enrichment means such as a filter using a membrane as a filter medium interposed in the engine's intake system.

<Operation> With this configuration, the oxygen concentration in the air supplied to the combustion chamber of the engine is increased, thereby reducing the nitrogen concentration, which is a factor in increasing the heat capacity of the generation system. The temperature of the flame is raised, thereby increasing the combustion efficiency.

<Example> Examples of the present invention will be described in detail below based on the drawings.

FIG. 4 is a schematic perspective view showing the overall configuration of an embodiment of the present invention, in which the intake system of the internal combustion engine 1 is composed of a main intake passage 2a and a sub-intake passage 2b, which are constructed in the same manner as before. Oxygen enrichment means 3 is interposed in the intake passage 2b.

The oxygen enrichment means 3 has an oxygen permeability coefficient of 2 to 2, for example.
3 x 10-'(cm' ・cm/cm2・5ec
-c+nH3) The filter is constituted by a filter using a strong thin film made of a polymeric material having an oxygen to nitrogen permeability coefficient ratio α of at least 2 or more and a thickness of about 1 to 0.1 am.

Specifically, we use various silicone polymers such as polydimethylsiloxane, their copolymers, and bulk polymers, as well as ultrathin film gases such as polyphenylene oxide, polymethylpentene, and polytrimethylvinylsilane. A filter using an oxygen-nitrogen (oxygen-nitrogen) membrane as a filter medium can be used.

In addition, the specific structure of the filter (oxygen enrichment means 3) is as follows:
For example, as shown in Fig. 2, a filter is used in which a gas separation membrane is formed into a cylindrical shape and the filter medium 3a is used, and as shown in Fig. 3, a filter is used in which a hollow tube or hollow fiber made of a gas separation membrane is used as the filter medium 3a. However, it is also possible to provide the air cleaner 4 with the function of the oxygen enrichment means 3 by incorporating a filter medium 3a made of a gas separation membrane inside the air cleaner 4 as shown in FIG. 4a is an air cleaner filter.

In the intake system of an internal combustion engine having such a configuration, when the engine is operated, a pressure difference is generated between the upstream and downstream sides of the oxygen enrichment means 3 due to the negative intake pressure, and this causes the filter medium 3a of the oxygen enrichment means 4 to Air passes through.

In addition, when such air passes (permeates), the permeability coefficient ratio between oxygen and nitrogen is set to, for example, 2 or more, so the engine contains oxygen-enriched air that has a higher oxygen concentration (lower nitrogen concentration) than normal air. oxidized air will be supplied.

Therefore, a large amount of fuel can be combusted in the same way as when conventional so-called supercharging is performed. However, since the absolute amount of nitrogen has decreased by an amount commensurate with the increase in oxygen concentration, the heat capacity of the combustion generation system has decreased and the flame temperature has increased, while the pumping loss has not increased. Since the absolute amount has been reduced in advance, the flow rate of exhaust gas (exhaust loss) is also reduced accordingly, and the amount of heat used within the combustion chamber increases, resulting in higher combustion efficiency.

The temperature of the flame increases as the oxygen concentration in the air supplied to the combustion chamber increases, but generally it increases significantly when the oxygen concentration increases by a few percent, and gradually decreases as the oxygen concentration increases. To increase. Therefore, by setting the capacity (ability) of the oxygen enrichment means 3 so that the final oxygen concentration is usually about 25 to 30 percent, fuel efficiency can be improved by about 20 to 30 percent. Can be done.

In the above embodiment, the intake system is composed of the main intake passage 2a and the sub-intake passage 2b, and the sub-intake passage 2b is interposed with the oxygen enrichment means 3, thereby achieving high-speed, high-load operation that requires a large amount of air. I try to ensure the intake flow rate at the time of
It is also possible to configure the intake system with only the passage provided with the oxygen enrichment means 3.

Further, as in the embodiment shown in FIG. 5, an air compressor 6 is provided which uses the starter 5 provided as a means for starting the engine as a driving source only when it is not operating (during normal operation of the engine). The discharge port and an air tank 7 attached to the engine 1 are connected via a passage 8 in which an oxygen enrichment means 3 is interposed, and a control valve 11 is interposed in a passage 10 leading from the air tank 7 to the intake manifold 9. Accordingly, oxygen-enriched air may be supplied to the engine in operating regions that require a large amount of oxygen, such as during engine startup, acceleration, high-load operation, and the like.

In Fig. 5, 2 is the same intake pipe as before, 12 is the engine speed,
The controller 12 is a controller to which various signals such as the accelerator opening, the pressure of the air tank 7, and the vehicle speed are supplied as driving information, and the opening and closing of the control valve 11 is controlled by the signals from the controller 12.

Further, as in the embodiment shown in FIGS. 6 and 7, an air nozzle 13 is connected via a control valve 11 to an air tank 7 connected to an air compressor 6 via an oxygen enrichment means 3,
By opening the air nozzle 13 into the combustion chamber 14, oxygen-enriched air can also be supplied directly to the combustion chamber 14. Furthermore, the air compressor 6 can be operated by opening the control valve 11 to return the air in the combustion chamber 14 to the air tank 7 in an operating range where the engine functions as a pump, such as when the engine brake (exhaust brake) is activated. The load can be reduced. In FIG. 6, 15 is an unloader valve.

In addition, when the air tank 7 is provided to store oxygen-enriched air in this way, the air tank 7 is connected to the engine 1 as in the embodiment.
It is desirable to reduce the pressure loss in the piping by installing it in the pipe.

In all of the above embodiments, the oxygen enrichment means 3 is configured with a filter using a gas separation membrane made of a polymeric material as a filter medium, so that oxygen (4 degrees Celsius) can be easily increased. For example, as shown in FIG. By employing the centrifugal type oxygen enrichment means 3 having the structure shown in Figure 3, the air is swirled at high speed within the oxygen enrichment means 3 and the oxygen concentration is increased by utilizing the difference in specific gravity between oxygen and nitrogen. It can also be made higher.

In addition, when an oxygen enrichment means is installed in the auxiliary intake passage of an air compressor as in the embodiment shown in FIGS. 6 to 8, the pressure difference between the upstream and downstream of the oxygen enrichment means is actively This increases oxygen enrichment efficiency and reduces engine suction loss.

<Effects of the Invention> As explained above, according to the present invention, since oxygen-enriched air with a higher oxygen concentration than normal air is supplied to the engine, exhaust flow rate and pumping loss, etc. are increased. It is possible to increase the amount of oxygen required for combustion without causing any damage, which increases the temperature of the flame and increases combustion efficiency, which significantly improves engine output, exhaust characteristics, and fuel efficiency. can be done.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing the overall configuration of a fourth embodiment of the present invention, and FIGS. Schematic cross-sectional view of main parts showing different embodiments of enrichment means, No. 5
The figure is a schematic side view showing the overall configuration of the second embodiment of the present invention,
FIG. 6 is a schematic side view showing the overall configuration of the third embodiment of the present invention, FIG. 7 is a sectional view taken along the line ■-■ in FIG. 6, and FIG. 8 is a schematic sectional view of oxygen enrichment means using a centrifugal minute method. It is.

Claims (6)

[Claims] (1) An intake system for an internal combustion engine in which an oxygen enrichment means is interposed in the intake system. (2) A patent characterized in that the intake system is composed of a main intake passage connected to the atmosphere via an air cleaner and a sub-intake passage connected to the atmosphere via an air cleaner and oxygen enrichment means. An intake system for an internal combustion engine according to claim 1. (3) An intake system for an internal combustion engine according to claim 1 or 2, wherein the oxygen enrichment means is constituted by a filter using a gas separation membrane made of a polymeric material as a filter medium. (4) The oxygen enrichment means is composed of a filter using a gas separation membrane made of a polymeric material as a filter medium, and an air compressor is interposed in the intake passage upstream of the filter, and an air tank is installed in the intake passage downstream of the filter. 3. The intake system for an internal combustion engine according to claim 2, further comprising a control valve interposed in the intake passage downstream of the air tank, the control valve being controlled to open and close according to the operating state of the engine. (5) The intake system for an internal combustion engine according to claim 4, wherein the downstream end of the intake passage is connected to the combustion chamber via an air nozzle. (6) An intake system for an internal combustion engine according to claim 4 or 5, wherein the air tank is attached to the engine body.